时间：2011-03-11 23:18来源：蓝天飞行翻译 作者：航空 点击：次
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radar beam. A beam of focused electromagnetic energy radiated by radar. It is similar to a flashlight or searchlight beam, except that the frequency of the electromagnetic energy is beyond the visible range. radar clutter (ICAO). The visual indication on a radar display of unwanted signals. “Radar contact lost” (air traffic control). A phrase used by ATC to inform a pilot that radar data used to determine the aircraft’s position is no longer being received or is no longer reliable, and radar service is no longer being provided. The loss may be attributed to several factors, including the aircraft merging with weather or ground clutter, the aircraft operating below radar line of sight coverage, the aircraft entering an area of poor radar return, failure of the aircraft transponder, or failure of the ground radar equipment. radar identification (air traffic control). The procedure for ascertaining that an observed radar target is the radar return from a particular aircraft. radar mile. The time in microseconds needed for a pulse of radar energy to travel a distance of one nautical mile and return to the radar receiver. One radar mile is approximately 12.4 microseconds. radarsonde observation (radar meteorology). A weather observation in which winds are measured by radar tracking a balloon-borne target. radial (electronic navigation term). A line of radio bearing radiating outward from a very-high-frequency omnirange (VOR) navigation facility. There are 360 radials radiating out from each VOR, and each radial is named for the number of degrees clockwise from magnetic north that the radial leaves the facility. radial bearing load. The load on a bearing that is perpendicular to the shaft on which the bearing is mounted. Centrifugal loads are radial loads. radial engine. A form of reciprocating engine that was at one time very popular for use on aircraft. The cylinders are arranged radially around a small central crankcase. Radial engines have an exceptionally good power-to-weight ratio, but they have so much frontal area that they cause an excessive amount of aerodynamic drag and are not efficient for modern high-speed airplanes. radial-inflow turbine. A type of turbine that uses a wheel similar to the wheel of a centrifugal air compressor. The hot exhaust gases that drive the turbine flow in through its outer rim and out its center. Radial-inflow turbines are used to drive the compressors in turbochargers for reciprocating engines. radial lead (electrical component). The lead of an electrical component, such as a resistor or capacitor, that protrudes from the side of the component (it radiates outward). The other type of lead used on these components is an axial lead, which sticks out straight from the center of the end of the component. radial outflow compressor (type of turbine engine compressor). This is another name for a centrifugal compressor. The air being compressed is drawn into the center of the compressor and thrown outward by centrifugal force, where it passes through the diffuser and then into the compressor manifold. |
